This week on HST

HST Programs: November 9 - November 15, 2009

Program Number Principal Investigator Program Title Links
11142 Lin Yan, California Institute of Technology Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3 Abstract
11153 Sangeeta Malhotra, Arizona State University The Physical Nature and Age of Lyman Alpha Galaxies Abstract
11235 Jason A. Surace, California Institute of Technology HST NICMOS Survey of the Nuclear Regions of Luminous Infrared Galaxies in the Local Universe Abstract
11360 Robert W. O'Connell, The University of Virginia Star Formation in Nearby Galaxies Abstract
11522 James Green, University of Colorado COS-GTO: STAR FORMATION/LYMAN-ALPHA Abstract
11548 S. Thomas Megeath, University of Toledo NICMOS Imaging of Protostars in the Orion A Cloud: The Role of Environment in Star Formation Abstract
11557 Gabriela Canalizo, University of California - Riverside The Nature of low-ionization BAL QSOs Abstract
11563 Garth Illingworth, University of California, Santa Cruz Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to <0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields Abstract
11565 Sebastien Lepine, American Museum of Natural History A search for astrometric companions to very low-mass, Population II stars Abstract
11572 David Kent Sing, CNRS, Institut d'Astrophysique de Paris Characterizing Atmospheric Sodium in the Transiting hot-Jupiter HD189733b Abstract
11573 Lawrence Sromovsky, University of Wisconsin - Madison Investigating Post-Equinox Atmospheric Changes on Uranus Abstract
11589 Oleg Y. Gnedin, University of Michigan Hypervelocity Stars as Unique Probes of the Galactic Center and Outer Halo Abstract
11592 Nicolas Lehner, University of Notre Dame Testing the Origin(s) of the Highly Ionized High-Velocity Clouds: A Survey of Galactic Halo Stars at z>3 kpc Abstract
11593 Michael C. Liu, University of Hawaii Dynamical Masses of the Coolest Brown Dwarfs Abstract
11594 John M. O'Meara, Saint Michaels College A WFC3 Grism Survey for Lyman limit absorption at z=2 Abstract
11599 Richard A. Wade, The Pennsylvania State University Distances of Planetary Nebulae from SNAPshots of Resolved Companions Abstract
11606 Dan Batcheldor, Rochester Institute of Technology Dynamical Hypermassive Black Hole Masses Abstract
11611 D. Michael Crenshaw, Georgia State University Research Foundation Are Narrow-Line Seyfert 1 Galaxies Viewed Pole-on? Abstract
11613 Roelof S. de Jong, Astrophys. Inst. Potsdam GHOSTS: Stellar Outskirts of Massive Spiral Galaxies Abstract
11643 Ann Zabludoff, University of Arizona A Timeline for Early-Type Galaxy Formation: Mapping the Evolution of Star Formation, Globular Clusters, Dust, and Black Holes Abstract
11644 Michael E. Brown, California Institute of Technology A dynamical-compositional survey of the Kuiper belt: a new window into the formation of the outer solar system Abstract
11646 Arlin Crotts, Columbia University in the City of New York Light Echoes as Probes of Supernova Type Ia Environments Abstract
11657 Letizia Stanghellini, National Optical Astronomy Observatories The population of compact planetary nebulae in the Galactic Disk Abstract
11661 Misty C. Bentz, University of California - Irvine The Black Hole Mass - Bulge Luminosity Relationship for the Nearest Reverberation-Mapped AGNs Abstract
11666 Adam J. Burgasser, Massachusetts Institute of Technology Chilly Pairs: A Search for the Latest-type Brown Dwarf Binaries and the Prototype Y Dwarf Abstract
11691 Paul Goudfrooij, Space Telescope Science Institute Using Massive Star Clusters in Merger Remnants To Provide Reference Colors of Intermediate-Age Stellar Populations Abstract
11704 Brian Chaboyer, Dartmouth College The Ages of Globular Clusters and the Population II Distance Scale Abstract
11714 Howard E. Bond, Space Telescope Science Institute Snapshot Survey for Planetary Nebulae in Local Group Globular Clusters Abstract
11730 Nitya Jacob Kallivayalil, Massachusetts Institute of Technology Continued Proper Motions of the Magellanic Clouds: Orbits, Internal Kinematics, and Distance Abstract
11731 C. S. Kochanek, The Ohio State University Research Foundation Studying Cepheid Systematics in M81: H-band Observations Abstract
11732 C. S. Kochanek, The Ohio State University Research Foundation The Temperature Profiles of Quasar Accretion Disk Abstract
11789 George Fritz Benedict, University of Texas at Austin An Astrometric Calibration of Population II Distance Indicators Abstract
11801 Holland Ford, The Johns Hopkins University Black Holes in Globular Clusters Abstract

Selected highlights

GO 11563: Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to <0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields

The ACS optical/far-red image of the Hubble Ultra Deep Field Galaxy evolution in the early Universe is a discipline of astronomy that has been transformed by observations with the Hubble Space Telescope. The original Hubble Deep Field, the product of 10 days observation in December 1995 of a single pointing of Wide Field Planetary Camera 2, demonstrated conclusively that galaxy formation was a far from passive process. The images revealed numerous blue disturbed and irregular systems, characteristic of star formation in galaxy collisions and mergers. Building on this initial progam, the Hubble Deep Field South (HDFS) provided matching data for a second southern field, allowing a first assessment of likely effects due to field to field cosmic variance, and the Hubble Ultra-Deep Field (UDF) probed to even fainter magitude with the Advanced Camera for Surveys (ACS). The highest redshift objects found in the UDF have redshifts approaching z~7. Pushing to larger distances, and greater ages, demands observatons at near-infrared wavelengths, as the characteristics signatures of star formation are driven further redward in the spectrum. The present program aims to extend observations beyond z~8 to z+9 or even 10 by using the WFC3-IR camera to obtain deep F850LP (Y), F105W (J) and F160W (H) images centred on the UDF and two flanking fields. Parallel observations with ACS will be used to extend the visible and red iamging data to even fainter magitudes.

GO 11593: Dynamical Masses of the Coolest Brown Dwarfs

Epsilon Indi Bab, the binary brown dwarf companion of the nearby K dwarf Brown dwarfs are objects that form like stars, but lack sufficient mass to drive the central temperature above a few million degrees, and therefore never succeed in igniting core hydrogen fusion. Discovered almost 15 years ago, these objects initialy have surface temperatures of ~3,500K, but cool rapidly and move through spcetral types M, L and T. Following their discovery, considerable theoretical attention has focused on the evolution of their intrinsic properties, particularly the details of the atmospheric changes in the evolution from type L to type T and beyond. This transition marks the emergence of methane as a dominant absorber at near-infrared wavelengths. Current models suggest this transition occurs at ~1400-1200K, and that the spectral changes are at least correlated with, and perhaps driven by, the distribution and properties of dust layers ("clouds"). The overall timescales associated with this process remains unclear. Mass is a crucial factor in mapping those changes, but mass is also the most difficult quantity to measure in a reliable fashion. The present proposal aims to tackle this issue through astrometry of ultracool binary systems, deriving the orbits and hence dynamical masses. Initially designed for ACS, the current observations are being made with WFPC2, and the binary system SDSSJ092615.38+584720.9 will be imaged in the coming week.

GO 11644: A dynamical-compositional survey of the Kuiper belt: a new window into the formation of the outer solar system

The view from Sedna: an artist's impression The Kuiper Belt lies beyond the orbit of Neptune, extending from ~30 AU to ~50 AU from the Sun, and includes at least 70,000 objects with diameters exceeding 100 km. Setting aside Pluto, the first trans-Neptunian objects were discovered in the early 1990s. Most are relatively modest in size, with diameters of a few hundred km and photometric properties that suggested an icy composition, similar to Pluto and its main satellite, Charon. Over the last three years, a handful of substantially larger bodies have been discovered, with diameters of more than 1000 km; one of the objects, 2003 UB313, is comparable in size to Pluto (2320 km.). At the same time, ground-based surveys, such as the Deep Ecliptic Survey, the Canada-France Ecliptic plane Survey and the Palomar Quest Survey, scanned the ecliptic for fainter, lower-mass objects, with the aim of using their properties to assess the likely chemical composition and dynamical history of the early Solar System. The present program will use Wide Field Camera 3 to push up to 2 magnitudes fainter than these ground-based studies, providing reliable estimates of compositions for a representative sample of KBOs.

GO 11730: Continued Proper Motions of the Magellanic Clouds: Orbits, Internal Kinematics, and Distance

The Large Magellanic Cloud (upper left) with the Small Magellanic Cloud (right) and the (foreground) Galactic globular cluster47 Tucanae The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are the most massive satellites of the Milky Way galaxy. The orbital motions of these systems can be used to probe the mass distribution of Milky Way, and backtracking the orbits can shed light on how the three systems have interacted, In particular, the well known Magellanic Stream, stretching between the two Clouds, is thought to be a product either of interactions between the Clouds, or of ram-stripping of gas from the LMC on its last passage through the Plane of the Milky Way. The present program builds on observations obtained at three previous epochs with the now-defunct ACS High Resolution Camera (ACS/HRC) and, in Cycle 16, with the Planetary camera on WFPC2. The previous programs targeted known QSOs lying behind the Clouds; the QSOs serve as fixed reference points for absolute astrometry of the numerous foreground LMC/SMC stars. First epoch observations were made in late 2002 (GO 9462), with the follow-up imaging in late 2004 (GO 10130) and 2007/2008 (GO 11201). The tangential motions of the Clouds amount to only a few milliarcseconds, but the high spatial resolution and high stability of HST imaging makes such measurements possible, even with only a 2-year baseline. Surprisingly, the initial results suggest that the 3-D motions of both clouds are much higher than expected, suggesting either that the LMC/SMC/MW is either dynamically very young, or unbound. The present program will use WFC3 to obtain fourth-epoch data in the same fields, providing a further crucial test of the initial results

Past weeks:
page by Neill Reid, updated 23/10/2009